Project Specification

Development Cycle

When you reach the project design phase you will begin to employ the development cycle. It is good to have a broad, macro-level design idea to get you started, but don’t make the mistake of trying to design everything up front. Design until you can begin coding and test some of your design ideas. The development cycle is summarized in table 3-2.

Table 3-2: Development Cycle

Step	Explanation
Plan	Design to the point where you can get started on the implementation. Do not attempt to design everything up front. The idea here is to keep your design flexible and open to change.
Code	Implement what you have designed.
Test	Thoroughly test each section or module of source code. The idea here is to try to break it before it has a chance to break your application. Even in small projects you will find yourself writing short test-case programs on the side to test something you have just finished coding.
Integrate/Test	Add the tested piece of the application to the rest of the project and then test the whole project to ensure it didn’t break existing functionality.
Refactor	This step applies more to object-oriented programming than to procedural programming. It means to take a comprehensive look at your overall application architecture and migrate general functionalityup into base, or even abstract, classes so the functionality can be utilized by more concrete derived classes.

Employ the development cycle in a tight spiral fashion as depicted in figure 3-1. By tight spiral I mean you will begin with the plan step, followed by the code step, followed by the test step, followed by the integrate step, optionally followed by the refactor step. When you have finished a little piece of the project in this fashion, you return to the plan step and repeat the process. Each complete plan, code, test, integrate, and refactor sequence is referred to as an itera-tion. As you iterate through the cycle you will begin to notice the time it takes to complete the cycle from the beginning of the plan step to the completion of the integrate step decreases. The development cycle spirals tighter and tighter as development progresses until you converge on the final solution.

Figure 3-1: Tight Spiral Development Cycle Deployment